diff --git a/chapter01/chapter01.xml b/chapter01/chapter01.xml
index 6aa1ab050..9d98c44ca 100644
--- a/chapter01/chapter01.xml
+++ b/chapter01/chapter01.xml
@@ -2,7 +2,7 @@
 <title>Introduction</title>
 <?dbhtml filename="chapter01.html" dir="chapter01"?>
 
-&c1-acknowledgments;
+&c1-acknowledgements;
 &c1-how;
 &c1-conventions;
 &c1-version;